16^ ^ 



PREFATORY NOTE. 



U. S. Geological, and Geographical 



Survey of the Territories, 



WasJiinfitou, July 31, 1882. 



Bulletin jS'o. 3 completes Volume VI and ends the series. With this 

 number are issued index, title-page, table of contents, list of illustra- 

 tions, &c., foi^ the whole volume. The separately published numbers 

 should be preserved for binding, as there is no issue of the Bulletins in 

 bound volumes, and as back numbers cannot always be supplied to 

 complete deficient files. 



In issuing the final volume of Bulletins, a word regarding the origin 

 and progress of this publication will not be out of place. The issue 

 began in 1874, when it was found desirable to establish more ready 

 means of communication with the public and with scientific bodies than 

 the regular reports of the Survey afforded; the design being to publish, 

 without tbe delay incident to the appearance of more elaborate and ex- 

 tended articles, such new or specially interesting matter as should be 

 contributed to the general results of the explorations under my charge 

 by the members or the collaborators of the Survey. The practical im- 

 portance of promi)t measures in such cases is well recognized, and suflS- 

 cientlj" attested by the success which the Bulletins have achieved. 



The First and Second Bulletins, which appeared in 1874, are sepa- 

 rately paged pamphlets, without ostensible connection with each other 

 or with subsequent ones, but together constituting a "First Series" of 

 the publication. Bulletins which appeared in 1875, being those of a 

 "Second Series" and six in number, are continuously paged. With 

 i^o. G were issued title, contents, index, &c., for all the numbers of both 

 "series" which had then appeared; the design being that these should 

 together constitute Volume I, in order that the inconvenient distinction 

 of "series" might be dropped. 



With Bulletin Xo. 1 of 1876, the publication was established as an 

 annual serial; the four consecutively imaged numbers of that year con- 

 stituting Volume II. 



The four Bulletins of 1877 constitute Volume III. 



The four Bulletins of 1878 form Volume IV. 



The four Bulletins of 1879 and 1880 constitute Volume V, and Volume 

 VI, which contains three numbers, issued during 1881 and 1882, closes 

 the publication. It is to be regretted that Article I of Xo. 3 remains 



